The number of newly confirmed Ebola infections in West Africa's outbreak region stayed at three last week for the third straight week, with Guinea the only country to report new cases, the World Health Organization (WHO) said today in its weekly snapshot of the epidemic.

Earlier this week, the WHO announced that Sierra Leone had gone a full week without reporting a new case, the first time since the outbreak began last year. However, in reporting further progress against the virus, the WHO also warned of a significant risk of transmission, because some contacts have been lost to follow-up in Guinea and in Freetown, Sierra Leone's capital.

In a related development, the WHO recently announced that a committee set up to review how the International Health Regulations (IHRs) performed during the Ebola outbreak will meet for the first time on Aug 24.

All 3 cases among contacts

All of Guinea's three Ebola cases were among registered contacts, and the patients are all receiving care in Ebola treatment centers, according to the WHO. The high percentage of detections in known contacts is an encouraging sign that surveillance activities have identified ongoing transmission chains.

Two of the patients are from Conakry's Matam area and relatives of a single case-patient reported from the capital's Ratoma area the previous week. The country's only other case was in Forecariah district, which had been a hot spot over the past several months.

Between Guinea and Sierra Leone there are about 800 contacts still under monitoring, about half the number of the week before. They are limited to three districts in Guinea and three in Sierra Leone. The WHO warned, though, that having a large number of people under observation still poses a risk of further transmission.

Liberia's last two Ebola patients were discharged on Jul 23 after testing negative twice, the WHO said. If the country goes until Aug 28 without another detection, it will reach Ebola-free status for the second time, Tolbert Nyenswah, who heads Liberia's incident management system, told Liberia News Agency (LINA) yesterday.

For the third straight week, no new Ebola illnesses were reported in healthcare workers, keeping the total at 880, including 512 deaths.

Over the course of the outbreak, the three countries have reported 27,952 confirmed, probable, and suspected Ebola infections, including 11,284 fatalities.

Ebola IHR committee to meet

At its meeting in May the World Health Assembly asked for a committee to assess the effectiveness of the IHRs during the Ebola response. The 16-member group will also look at links to the WHO's emergency response framework and other humanitarian responsibilities. In 2010, a similar committee reviewed IHR performance during the 2009 H1N1 pandemic.

The IHRs have faced criticism in other reviews of the Ebola response. For example, an independent review committee appointed by the WHO found that many countries haven't met their IHR core capacities, which likely contributed to the spread of the virus and the slow response to the epidemic. Other observers have noted that the IHRs in their current form didn't prevent countries from imposing travel and trade restrictions, which were also thought to have impeded the response to the crisis.

In a recent announcement, the WHO said the committee will meet on Aug 24 and Aug 25 in Geneva and that the committee chair will hold a press conference on Aug 25 at the conclusion of the event.